Background: Vestibular function declines with age, and emerging evidence suggests that vestibular loss is associated with cognitive impairment. Whether vestibular dysfunction is associated with age-related cognitive decline is unknown.
Methods: We used data from the 1999-2002 National Health and Nutrition Examination Surveys to evaluate the influence of vestibular function on cognitive performance in a nationally representative sample of U.S. adults aged ≥60 years (n = 1,303). Vestibular function was measured with the modified Romberg test, and cognitive function was measured by the digit symbol substitution (DSS) score test. We also developed structural equation models (SEMs) to explore whether vestibular dysfunction and associated cognitive impairment mediate the effect of age on falls and activities of daily living (ADL) difficulty.
Results: Vestibular dysfunction was present in 58% of the study population. In multivariate analyses, vestibular dysfunction was associated with a 3.4-point lower DSS score (95% confidence interval: -5.2, -1.6; p < .0001), equivalent to the effect of 5 years of age. Vestibular dysfunction was also associated with a significantly higher odds of ADL difficulty (p = .001), and with a 2.6-fold increase in the odds of falling (p = .017). SEMs suggested that vestibular function mediates 14.3% of the effect of age on cognitive performance. Further SEMs suggested that lower cognitive performance mediates the association between vestibular loss and ADL difficulty as well as falls.
Conclusions: This study suggests that vestibular dysfunction partially mediates the association between age and cognitive impairment. Moreover, the cognitive impairment that results from vestibular loss may contribute to ADL difficulty and falls in older individuals.
Keywords: Balance; Cognition; Cognitive Aging; Falls; Functional Performance.
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